648 



SUMMARY OF CUERBNT RESEARCHES RELATING TO 



the lecturer beyond the need of a lantern assistant. The table consists 

 of an under part and of a set-back upper part ; both parts are of pine 



Fig. 148. 



wood with oaken tops. The upper part is hinged, in the neighbour- 

 hood of the electrical terminals, to the lower, and the opposite face can 



be raised — this movement would be advantageous 

 in lecturing to a large assembly. Both upper and 

 lower parts are fitted up as cabinets, which are 

 convenient receptacles for the various fittings and 

 auxiliaries. Incandescent gas, acetylene, lime, or 

 electric light can be used, of which the last-named is 

 undoubtedly the best. The makers strongly recommend their self- 

 regulating differential arc lamp in preference to a hand-controlled one. 

 Proper attention must be paid to current strength and resistance. 



Fig. 149. 



